Exemplary embodiments of the present invention relate to a method for fabricating a semiconductor device, and more particularly, to a doping method for a semiconductor device that may dope a particular region without performing an ion implantation process.
Ion implantation is usually used to dope a particular portion, e.g., a junction region, when a semiconductor device is fabricated. The ion implantation may control the doping depth and doping concentration.
However, as semiconductor devices become highly integrated, more complicated three-dimensional (3D) structures may be formed. In this case, if an etch process for forming a 3D structure is performed after a doping process is performed through ion implantation, it may become difficult to form a desired 3D structure because etch characteristics may become different in the area where the doping process is performed.
Therefore, the doping process may be performed through the ion implantation method after a 3D structure, such as a trench, is formed. In this case, however, a portion which is not desired to be doped, that is, an uncontrollable doping region, may be formed. Also, since the ion implantation method requires high energy and a dopant is implanted through a lattice, defects may be caused due to ion bombardment. Although the defects may be reduced through a subsequent thermal treatment, the defects are not completely removed.
Therefore, it may be difficult to form a doping region at a desired position without a defect through ion implantation.